1. Field of the Invention
The present invention relates to a process for burning off oil spills using an incendiary material and preferably a priming compound, and especially for burning off oil spills on lakes, seas or marginal seas or in the soil of coastal areas.
2. Background of the Invention
Oil spills on lakes, seas or marginal seas and in the soil of coastal areas usually cause considerable environmental pollution and damage. Animals and plants immediately suffer substantial damage. The damage to zooplankton and phytoplankton can result in the disappearance of the vital food supply for numerous marine animals in the affected area and can endanger the entire local ecosystem. Disasters due to oil spills are very often caused on the oceans by damaged tankers or incidents on drilling rigs, but they can also be caused by illegal tank flushing. Experience has shown that the consequences of oil disasters cannot be satisfactorily remedied using the conventional technologies.
Transported crude oils sometimes have very different compositions. Different deposits produce crude oils of different composition; also, considerable amounts of heavy crude oils emulsified e.g. with nonylphenol ethoxylate are transported. Individual oil accidents are therefore seldom comparable to one another. Specific types of oil contain more volatile and better combustible or miscible components. The outcome of the disaster is also influenced by the air and water temperatures and by the solar irradiation in the region of the accident. These temperatures influence particularly the evaporation of the readily volatile oil components. The less volatile constituents are left behind as a slick, floating on the water, and over time are dissolved or emulsified in the seawater, are absorbed by plankton or agglomerate into lumps. Parts of the oil slick invade coastal areas and form a sticky mass. If the oil slick sticks to rocky cliffs and reefs, it forms tar-like lumps which take several years to be decomposed by bacteria.
Mechanical suction is used as a simple method of treatment. This method can be applied on the high seas only in the case of compact oil slicks and on the beach only in the case of a freshly washed-up slick. The use of inflated plastic tubes for containment and suction, optionally in combination with skimmers, is problematic even on a slightly choppy sea because it is normally impossible to prevent a troubled sea from splashing over the oil slick. Applications based on the use of surfactants are also of dubious value because of the tricky dosing problems. This is compounded by the fact that emulsifiers very often act as environmental pollutants. After the uptake of small amounts of oil as a result of emulsification, they sink to the bottom of the sea or lake, where they cause damage to the flora and fauna.
The use of oil-decomposing bacteria requires warmer temperatures, an adequate oxygen supply and a long contact time. The essential aspect of oil removal, however, is that it can be achieved quickly so as to minimize the environmental damage.
It has now been found that spills of oil, including heavy and viscous oil, in the form of oil slicks on water surfaces such as lakes or seas, or in the soil, can be ignited and extensively burnt off in a short time if, prior to ignition, the oil slick is sprayed with a readily combustible mixture of saturated and/or unsaturated hydrocarbons, preferably with a mixture of saturated hydrocarbons (also referred to as “incendiary material” hereafter), and the oil slick soaked with this mixture is then ignited. Surprisingly, the oil slick can be completely or almost completely burnt off in this way without exhibiting the above-mentioned disadvantages, even if it contains relatively high proportions of components of low volatility.